Blind plug for use with a fluid proof connector



March 26, 1968 A. l.. NELSON 3,375,480

.BLIND PLUG FOR USE WITH A FLUID PROOF CONNECTOR- Fled Dec. 15, 1965 I6l 28- 23 26 29 IO 24 22 I7 Y A 20 Fla. le 25 I7 |023 s 24 :9 22

mW/Pi?" `T r////////////////// j 7///////////////////// I INVENTOR. ARTHUR L. NELSON ATTORNEYS United States Patent Office 3,375,480 Patented Mar. 26, 1968 3,375,480' BLIND PLUG FOR USE WITH A FLUID PROOF CONNECTOR Arthur L. Nelson, San Diego, Calif., assigner to Winsco Instruments & Controls Company, Inc., a corporation of California Filed Dec. 15, 1965, Ser. No. 513,974 3 Claims. (Cl. 339-38) ABSTRACT OF THE DISCLOSURE This disclosure relates to a blind plug for underwater use with fluid proof connectors such as shown in United States Patent 3,277,424. This connector comprises acylindricail socket body open at both ends and arranged to receive a power plug in one end in the form of a cylindrical plug body. The plug body and interior cylindrical wall of the socket include contact means which will engage wfhen the cylindrical plug is received within one end of the cylindrical socket. The t is snug so'as to provide a fluid proof connection. The blind plug on the other hland isreceifv'able in the other end of the socket wlhen the power plug is not being used and the blind plug includes contact means for engaging the socket contact but the contact means in the blind plug terminates wholly Within the plug so that no electrical energy can pass from the blind plug. With the blind plug inserted in the socket, the power plug may be inserted in the one end and engage the blind plug to urge it out the other end as the power plug is positioned in the socket such that a complete uid proof connection can be effected without ever exposing the socket Contact to the ilurid environment.

This invention relates to a specially designed blind plug for use with connectors for enabling the connection of two or more conductors together in a fluid proof environment even though one or more of the conductors is connected to a source of electrical energy and the surrounding fluid itself may be conductive.

In my co-pending application, Ser. No. 490,256, filed Sept. 27, 1965, and entitled, Fluid Proof Connector, now United States Patent No. 3,277,424, there is described in considerable detail electrical connectors prif marily designed for effecting connections under water, although the connectors themselves are useful in other fluid environments such as gases, or even in explosive atmospheres.

The basic design feature in the foregoing types of connectors resides in the provision of a socket body having an elongated socket open at both ends for cooperation with a plug body having an elongated plug of dimensions correspond-ing to those of the socket and receivable in one end olf the socket. The socket and plug, respectively, include socket and plug contacts intermediate their ends such that when the elongated plug is urged into one end of the socket, wlater or other fluid in the socket is urged out the opposite end, and the interior surfaces of the socket .and exterior surfaces o-f the plug are wiped clean of any fluid or other foreign matter. Thus, the integrity of the electrical connection when the plug contact is positioned within the socket contact is assured.

Since the socket is open at both ends, when-the plug is separated from the socket, the socket contacts as well as the plug contacts are exposed to water or other fluids.

In the case of underwater operations, the problem of l exposed contacts is normally not serioussince the connectors involved are u's-ulally connected together or disconnected prior to the application orf any power to conductors leading to the connectors. There are instances,

however, in which it would be desirable to maintain the socket contact or contacts at all times clean and dry and insulated from the water even'though a corresponding plug has not been connected to the socket. Moreover, when one or more of the socket contacts are connected to a source of electrical energy, i-t would be desirable to enable the p-lug to be inserted in the socket and the plug contact or contacts connected to the socket contact or contacts without at any time exposing the socket contacts to the surrounding water or other fluid medium.

With the foregoing considerations in mind, it is accordingly a prim'ary object of this invention to provide a blind plug for use in underwater operations with a fluid proof connector in which plug andsocket contacts can be connected together or disconnected without at any time exposing the socket contacts to the uid environment and without sacrificing any of the desirable advantages of the lluid proof connect-or as fully described in the above referred to co-pending application.

More particularly, it is an object to pro-'vide a blind plug struct-ure for cooperation with a connector in such a manner as to enalble electrical connections to be made or broken under water without exposing certain ones of the contacts to the water and yet realizing the various advantages of providing a completely insulated connection.

Brietly, these and other objects and advantages of this invention are attained by providing a blind plug normally received in an end of a socket opiposite the open end normally receiving a plug. The blind plug constitutes an elongated plug of insulating material so as to completely insulate the socket contacts in the socket body. When it is desired to effect an electrical connection, an elongated plug having plug contacts normally connecting to 'a device to be powered is inserted in the end of the socket opposite the end receiving the blind plug. As the plug is urged into the socket, the blind plug is urged out orf its other end so that at no time yare the socketcontacts exposed to the water or other fluid environment With such an arrangement, the socket contacts may at all times,fif desired, be connected to a source of electrical energy, and there is no need to turn power ott1 during the mlalcing or breaking of an electrical connection.

A better understanding of the invention will be had by now referring to one elrnfbodlment thereof as illustrated in the accompanying drawings, in which:

FIGURE 1 is a perspective View of a socket body, plug, and blind plug body for use with the socket in accord with the invention;

FIGURE 2 is a fragmentary cross section of the components illustrated in FIGURE 1 preparatory to eifecting an electrical connection between the plug and socket bodies;

FIGURE 3 is a view similar to FIGURE 2 illustrating intermediate positions of the various components as an electrical connection is being made; and,

FIGURE 4 is still another View similar to FIGURES 2 and 3 but illustrating the relative positions of the components after an electrical connection has been completed.

Referring first to FIGURE l, there is shown a socket body 10 arranged to cooperate with a plugbody 11. The socket body includes conductor means in the form of leads 12 and 13 connecting to a source of electrical energy schematically indicated at 14. These leads extend to contacts within the body by wayA of an insulated cable 15. A blind plug 16 is received within an'open end of an elongated socket passing through the socket body 10, all as will become clear as the description proceeds.

The plug body 11 includes an elongated plug 17 including plug contacts 18 and 19 connecting to conductor leads 20 and 21 passing from the plug body for connection to any suitable device to be powered from the source 14. The elongated plug 17 is receivable in the end of the socket opposite the end receiving the blind plug 16.

Referring particularly to FIGURE 2, the elongate-d socket in the socket body is shown at 22 and includes socket contacts 23 and 2.4 embedded in the interior wall of the socket 22 and connecting to the conductors 12 and 13. These contacts are preferably in the form of split rings so that they are capable of circumferential expansion and contraction. The interior contact surfaces of the contacts 23 and 24 extend slightly beyond a fiush relationship with respect to the interior wall of the socket 22 so that the exposed contact surfaces are directed radially inwardly towards the central axis of the socket.

The blind plug body 16 includes a blind plug 2 5 of insulating material; preferably, there are included plug contacts 26 and 2.7. The plug contact 26 constitutes an enlarged exterior portion of acylindrical member 28 terminating within the blind plug body 16. The plug con tact 27 in turn constitutes an enlargement on a central rod 29 passing down the elongated plug 25 and also terminating within the plug body 16.

In the embodiment illustrated, there are no electrical connections made fto the contacts 26 and 27, these contacts constituting dummy contacts for simply engaging the split ring contacts 23 and 24 within the socket 22. The elongated rod portion 29 provides stiffening for the plug 25 to facili-tate insertion of the blind plug in the left end of the socket 22.

The plug body 11 shown to the right in FIGURE 2 incorporates an elongated rod 30, the end portion of which is enlarged to define the plug contact 18. The plug Contact 19, in turn, constitutes an enlarged cylindrical portion of a cylindrical tube 31. As shown, the rod 30 and inner right end of the cylindrical tube 31 connect, respectively, to the conductors 20 and 21 in the plug body 11. The rod 30 provides stiffening as well as an electrical connecting means between the lead 20 and the plug contact 18 so that insertion of the plug 17 in the socket 22 is facilitated.

The cross-sectional dimensions of the blind plug 25 and elongated plug 17 correspond to the cross-sec-tional dimensions of the socket 22 in the socket body 10 so that a snug relationship exists when either one of the plugs is received in the socket.

With the components in the position illustrated in FIG- URE 2, it will be evident that the blind plug 25 cornpletely insulates the socket contacts 23 and 24 from any fiuid environment and also from each other. Thus, a source of electrical energy such as indicated at 14 in FIGURE 1 connected to Vthese contacts will not be inadvertently short-circuited nor will there 'be any low resistance path therebetween as a consequence of a conducting fiuid environment.

The operation of the fluid proof connector and blind plug assembly may 'be understood by referring now to FIGURES 3 and 4. When it is desired to effect an electrical connection with the plug body 11, the plug 17 is urged into the open end of the socket 22. opposi'te the end receiving the blind plug 25. The end of the plug 17 will thus engage the end of the plug 25 and urge the same out from the socket as the plug 17 is urged into the socket. This positioning of the components is illustrated in FIG- URE 3 wherein the plug 17 is urged partially into one end of the socket 22 and =the blind plug 25 urged partially out of the other end of the socket.

Continual urging of the plug 17 into the righthand end of the socket will finally result in the blind plug 25 being completely ejected from the left end of the socket, the plug contacts 18 and 19 effecting electrical connection with the socket contacts 23 and 24. This last positioning is shown in FIGURE 4.

It will be evident from the foregoing that the electrical connections between the various leads in the sockets and plug bodies has been effected without in any manner exposing the socket contacts to the fluid environment. It

is thus possible to effect such electrical connection while the socket contacts are connected through the leads 12 and 13 directly to a source of electrical energy.

When it is desired to disconnect the plug body from the socket body, the blind plug 25 is urged into the left end of the socket to bear against the end of the plug 17 and urge it out of the socket to the right. When the blind plug is completely received within the socket, the plug 17 will be free of the socket as depicted in FIGURE 2, and again the socket contacts will have been completely insulated at al1 times from the surrounding uid.

From the foregoing description, it will be evident that the presen-t invention has provided an improved blind plug for a fiuid proof connector which will enable connections to be made or broken while under water or in other conducting fluid environments, eve-n though certain ones of the contacts may be at all times connected to a source of electrical energy.

While the blind plug has been described as insulating the socket contacts from the surorunding fluid as well as from each other, it is possible, of course, to connect the blind plug contacts themselves internally together so that insertion of the blind plug in a socket will intentionally short-circuit the socket contacts. This arrangement might be useful wherein the socket body and socket contacts themselves simply constitute a series connection in a line and the series connection can be completed by shorting the socket contacts together. In such an instance, another blind plug would be incorporated in the opposite end, and the first mentioned blind plug in which the plug contacts are shorted together internally of the lplug would be inserted in the other end of the socket to effect connection between the socket contacts themselves.

As a consequence of the foregoing, the present invention is not to be thought of as limited specifically to blind plugs for enabling only one type of underwater connection to be made wherein there is always necessary a plug having contacts connected to electrical conductors leading from the plug. In this respect, it should be understood that the blind plug described herein and having internal connections between its contacts could be useful in junction box structures such as shown and described in co-pending patent application, Ser. No. 512,340, led Dec. S, 1965, for Fluid Proof Junction Box, to effect desirable internal connections in the junction box,

In addition, the blind plug with disconnected or blind contacts as illustrated in the drawings would also be useful in the junction box for temporarily closing off junction box sockets not being used.

Thus, the blind plug may readily be used with any one of a number of different types of fluid p-roof devices and connectors and is therefore not to be though of as limited to the one type of connector or any particular application as illustrated herein merely by way of example.

While the cross-sectional dimensions of the plugs have been defined as corresponding substantially to the crosssectional dimensions of the sockets, it is meant -by these terms that the dimensions are such as to realize a desired interference type fit o-r snug-fit configuration sufiicient to provide a complete fluid proofing. Thus, the socket could be purposely molded to a slightly smaller internal diameter than the blind plug external diameter or other plug external diameter thereby resulting in a force-fit, the internal diameter expanding somewhat as a consequence of the resilient material of the socket. These very slight differences in cross-sectional dimensions are deemed to Ibe encompassed within the statement that the cross-sectional dimensions correspond to each other.

What is claimed is:

1. A blind plug body for use in a fiuid proof connector including a socket lbody having an open-ended cylindrical socket with socket contact means for receiving a plug in one end, said blind plug body including: an elongated cylindrical plug of insulating material and of cross-sectional dimensions corresponding to the cross-sectional dimensions of said socket, said blind plug being receivable in the yother end of said socket and including Iplug contact means in its exterior surface :positioned to engage said socket contact means when said blind plug is received in said socket, said plug contact means terminating wholly in said blind plug body so as to be incapable of passing electrical energy exterior to said blind plug body, whereby said socket contact means is insulated from any iluid environment exterior of said socket body and whereby a plug may be inserted in said o ne end to engage and urge said blind plug out said other end of said socket thereby enabling a power lconnection `to be effected without exposing said socket contact means to any iluid exterior of said socket body.

2. A- blind plug for use in -an elongated cylindrical socket having socket contact means in its interior wall, said blind plug comprising: a body portion including an elongated cylindrically shaped plug of insulating material and of cross-sectional dimensions corresponding to thc cross-sectional dimensions of said socket, said plug being receivable in said socket and including plug contact means in its exterior surface positioned to engage said socket contact means when said plug is received in said socket,

said plug contact means terminating wholly in said blind plug so as to be incapable of passing electrical energy exterior to said blind plug whereby said socket contact means is insulated from any uid environment exterior of said socket body.

3. A blind plug according to claim 2, in which said plug contact means includes a central rod imbedded in said plug and including an enlarged portion exposed on the exterior of said plug, said rod extending axially over a major portion of said plug and terminating in said body portion to provide stilfening for said plug.

References Cited UNITED STATES PATENTS 2,101,345 l2/1937 Riley 339--38 2,407,894 9/1946 Miller 339-38 2,428,323 9/1947 Winer 339-38 3,277,424 10/1966 Nelson 339-94 20 MARVIN A. CHAMPION, Primary Examiner.

I. H. MCGLYNN, Assistant Examiner. 

